Most of the basic components that make up a typical residential building envelope are mandated by Building Codes, but there are options that could enhance performance. And, when it comes to the efficiency of utility systems and availability of materials/finishes that improve overall home-health quality, much more can be done now than in the past.
The most obvious method of maintaining an energy-efficient perimeter in an existing home would firstly be to have your wall/attic components inspected, then upgraded, where necessary. Though new home Building Code Standards are well established, older homes often fall short of current goals, especially if the wall studs are 2x4’s rather than 2x6’s.
Insulation R-Value can be increased in these 2x4 walls from R-12 (or less) to a minimum of R-20 in a number of ways. Working from the interior, 2x4 walls can be “strapped out” to equal the depth of 2x6 walls, then re-insulated up to R-20 by increasing existing “batt” thickness, or by spray-foaming the 2x4 wall cavities, which would provide a minimum of the R-20 now required. This approach is fine if you are planning an extensive interior renovation, but working from the exterior usually makes more sense, especially if windows, doors and building wrap are also being changed-out as part of your energy waste reduction efforts.
Exterior cladding would have to be removed to allow for an insulation upgrade such as expanding foam to be injected into the wall cavities through holes drilled in the wall sheathing. The other option would be to install 1-2” thick panels of rigid foam over the wall sheathing and a new Tyvek building wrap. Either method should provide the R-20 standard. In addition, double or triple glazed windows with a Low-E coating and Argon gas in the sealed glass units will deliver effective protection from the sun’s UV rays and help reduce heat/cold transfer. Also desirable are solid-core or insulated entry doors. Attic areas should have a minimum of R-35 to R-40 batt or blow-in insulation. Attention should be paid to ensuring that attic-to-soffit circulation venting is not plugged. In the basement, joist-ends should be insulated, covered with a vapour-barrier and properly caulked.
This brief overview of building envelope topics would be among those addressed during a professional consultation regarding renovations or the building of a new home. Building systems and health-smart materials/finishes should also be examined at the same time, for a comprehensive home-health assessment. A few points to include in your discussion:
- Heat recovery ventilation (HRV)
- Ducting improvements
- Tankless water heaters
- Waste-water heat recovery
- Programmable thermostats
- LED lighting upgrades
- Air transfer testing
- Radon gas testing & mitigation
- Low VOC paint & carpeting
A Channel Custom Builders representative can help shed light on these somewhat complex issues. Contact Channel today to arrange for a complementary In-Home Consultation.